Seconds out, round two begins. This time last year, NASA revealed that the truly remarkable Mars Ice House had won the first phase of the 3D printed Habitat Challenge. The remarkable ice-shelled design simply seemed like the most efficient and realistic way to house space explorers on the harsh surface of Mars, but this challenge is a three-part race. NASA has just launched phase two, calling on inventors to further improve their designs to rely on resources readily available on Mars. While the first phase was about dreaming and design, the second phase is thus about construction, and this time a $1.1 million prize money pool is up for grabs.

But the goal remains the same: to pioneer new methods for the construction of homes where space explorers can live and work – relying on available and recyclable 3D printable materials as much as possible. The focus of phase two is more about the second dimension, and competitors are asked to “demonstrate a recycling system that can create structural components using terrestrial and space-based materials and recyclables,” the NASA Centennial Challenges website says. Building the structures dreamt up in phase one is thus imperative, and new systems will need to be developed.

These demands could make this a difficult race for the team that designed the previous Mars Ice House winner – which featured an ice shell consisting of vertically constructed nested domes, enclosed by a transparent ETFE membrane. While not only a very efficient way to generate space, it also provided a shield that protects inhabitants from the cosmic rays of the Martian atmosphere. The design further encapsulated a hydroponic greenhouse that provides additional food and oxygen to the crew and an occupiable ‘front’ yard – a unique interstitial zone where astronauts can roam freely without having to don a cumbersome EVA suit. While perfectly taking the scientific and psychological demands of Mars exploration into account, 3D printing the Mars Ice House is another challenge entirely. To realize it, the team would thus have to develop a way to extract Martian ice and 3D print into domes and other structures. Other recyclable materials can be used too.

If viable, NASA could one day use these phase 2 entries to build Mars shelters in the future, while the same concepts could be applied to affordable housing projects here on earth. “Shelter is an obvious necessity as we prepare to explore worlds beyond our home planet, but space and weight aboard our vehicles are precious, and taken by the many other resources we will need for survival,” said Steve Jurczyk, associate administrator for NASA’s Space Technology Mission Directorate. “That’s why we are seeking the technology to reuse the materials we will already be carrying, and combine them with what is already available at our destination, which is, in this case, soil. We recycle here on Earth – why not on Mars?”

Also involved in phase two of the competition are specialists from Brick & Mortar Ventures, Bechtel, Caterpillar and Bradley University. “Innovation, collaboration and experiential learning, three of Bradley University’s core values, are at the heart of the 3D-Printed Habitat Challenge with NASA and Caterpillar,” said Bradley University President Gary Roberts. “The challenge provides an unparalleled opportunity for students and faculty to network, create relationships with mentors and explore new ideas as they partner in creating solutions for our world and beyond.”

Interested teams can now register for phase two, with registration remaining open until 31 January, 2017. The challenge will culminate in a ground competition in August 2017 at Caterpillar in Edwards, Illinois, where facilities will be provided. A second round at Caterpillar will be held in 2018. For more information, check out the NASA competition page here.

The NASA 3D Printed Habitat Challenge is part of NASA’s Centennial Challenges Program, which uses competitions to interact with private inventors and researchers from very diverse backgrounds. The Program is part of NASA’s Space Technology Mission Directorate, and will host phase three of this 3D printing challenge. Phase 3 will open the summer of 2017, targeting the autonomous manufacturing of the habitats using 3D Printed technology.